1. Technical Field
The present invention relates to a liquid droplet ejecting head, a method for manufacturing the same, and a liquid droplet ejecting apparatus.
2. Related Art
For example, in a liquid droplet ejecting apparatus such as an ink jet printer which is available for an image recording apparatus, a display manufacturing apparatus and the like, a piezoelectric element has been extensively used for a liquid droplet ejecting head for ejecting liquid droplets such as ink. In relation to such a piezoelectric element, for example, a piezoelectric body is deformed by the voltage of a driving signal and the like applied thereto, so that a diaphragm formed under the piezoelectric element is deformed, resulting in a change in the volume of a pressure chamber. Thus, the liquid droplet ejecting head may eject liquid droplets such as ink which is supplied to the pressure chamber through nozzle holes.
In a member constituting such a liquid droplet ejecting head, for example, a support substrate including a silicon substrate and the like has been well known as a member for protecting the piezoelectric element (refer to JP-A-2007-176030).
When such a support substrate is formed and glued to a substrate having the piezoelectric element, for example, a manufacturing method shown in FIG. 13 has been well known. First, for example, a hard mask layer is formed on a silicon substrate through a sputtering method and the like (S111). Next, an exposure/development process is performed using a photolithography technology, so that a resist layer with a desired pattern is formed (S112 and S113). Then, the hard mask layer is etched using the resist layer so as to have a desired shape (S114). Thereafter, an unnecessary resist layer is removed (S115). Further, for example, by the use of an etching technology such as wet etching using the hard mask layer, an area serving as a space for protecting the piezoelectric element, a through hole for an ink supply fluid path, and the like are formed in the silicon substrate, so that a support substrate is formed (S116). Next, an adhesion process using adhesive is performed in order to glu the support substrate to the substrate having the piezoelectric element (S117 and S118). For example, the adhesive is transferred and coated on an adhesive portion of the support substrate (S117) and the substrate having the piezoelectric element is glued to the support substrate, so that the piezoelectric element is protected by the support substrate (S118 and S120).
In the case of using the adhesive in order to glue the support substrate to the substrate having the piezoelectric element, since the adhesive has viscosity, the adhesive may not easily be coated with a certain thickness or less and has fluidity. Therefore, it is probable that the adhesive may flow into an ink supply path formed in a fluid path forming plate at the time of the gluing process and the ink path may not be sufficiently ensured. Further, in the case of using the adhesive having fluidity, it is probable that liquid dripping and the like may occur in the transfer process of the adhesive, thereby causing the reduction in the yield in the manufacturing process.